MLA

Johnson, James Weldon, 1871-1938. Roosevelt, Eleanor. Box 17, folder 409. 1933. https://collections.library.yale.edu/catalog/2036305.

APA, 6th edition

Johnson, James Weldon, 1871-1938. (["Box 17, folder 409"])(1933)[Roosevelt, Eleanor]. https://collections.library.yale.edu/catalog/2036305.